scholarly journals Characterization and Cytotoxicity Comparison of Silver- and Silica-Based Nanostructures

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4987
Author(s):  
Elżbieta Adamska ◽  
Karolina Niska ◽  
Anna Wcisło ◽  
Beata Grobelna

Core-shell structures are the most common type of composite material nanostructures due to their multifunctional properties. Silver nanoparticles show broad antimicrobial activity, but the safety of their utilization still remains an issue to tackle. In many applications, the silver core is coated with inorganic shell to reduce the metal toxicity. This article presents the synthesis of various materials based on silver and silica nanoparticles, including SiO2@Ag, Ag@SiO2, and sandwich nanostructures—Ag@SiO2@Ag—and the morphology of these nanomaterials based on transmission electron microscopy (TEM), UV-Vis spectroscopy, and FT-IR spectroscopy. Moreover, we conducted the angle measurements due to the strong relationship between the level of surface wettability and cell adhesion efficiency. The main aim of the study was to determine the cytotoxicity of the obtained materials against two types of human skin cells—keratinocytes (HaCaT) and fibroblasts (HDF). We found that among all the obtained structures, SiO2@Ag and Ag@SiO2 showed the lowest cell toxicity and very high half-maximal inhibitory concentration. Moreover, the measurements of the contact angle showed that Ag@SiO2 nanostructures were different from other materials due to their superhydrophilic nature. The novel approach presented here shows the promise of implementing core-shell type nanomaterials in skin-applied cosmetic or medical products.

2017 ◽  
Vol 886 ◽  
pp. 48-52
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck

Pt-based nanoparticles (NPs) have numerous applications, such as, as catalyst, in car exhaust systems, gas sensors, biosensors and cancer therapy. One of the Pt based NPs which has been successfully produced is core-shell Ag@Pt NPs. Numerous methods for the synthesis of this material have been reported. This paper reports a fully new approach of chemical mediated synthesis for core-shell Ag@Pt NPs. Characterization process for the synthesized Ag@Pt NPs, carried out by the UV-vis Spectroscopy, Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HRTEM) showed that the core AgNPs have approximate sizes of 18 nm in diameter are shelled with Pt and the sizes of core-shell Ag@Pt NPs were estimated to be around 29 nm in diameter.


Author(s):  
Luong Huynh Vu Thanh, Tran Nguyen Phuong Lan Luong

This study aims to synthesize and characterize Fe3O4@SiO2 sub-nanoparticles (SNPs) with high saturation magnetization (SM). The research process was conducted in simple and environmentally friendly conditions. The results of ultraviolet-visible (UV-Vis) spectroscopy and X-ray diffraction (XRD) analysis presented that the Fe3O4@SiO2 SNPs were well formed and the phase change of Fe3O4 NPs did not happen in Fe3O4@SiO2 SNPs. Transmission electron microscope (TEM) analysis showed that the Fe3O4@SiO2 SNPs are in a fairly spherical shape with a core/shell structure and a diameter in a range of 100 nm to 500 nm. Fourier transform infrared spectrometry (FT-IR) spectra of Fe3O4@SiO2 SNPs presented some absorption peaks indicating the existence of Si-O-Si, O-Si-O, Fe-O and Fe-O-Si. The SM of Fe3O4 particles and Fe3O4@SiO2 SNPs determined via vibrating sample magnetometer (VSM) were 50.9 emu.g−1 and 19.5 emu.g−1, respectively. All the above results provide clear evidence that the Fe3O4 particles were coated by SiO2 to form sub-nano core/shell with great SM.


2021 ◽  
Author(s):  
Amalanathan.M ◽  
Aravind.M ◽  
Sony Michael Mary.M ◽  
Razan A. Alshgari ◽  
Asma A. Alothman ◽  
...  

Abstract In this work, jasmine flower derived activated carbon were successfully synthesized by hydrothermal carbonization process at the different annealing temperature. The Crystallinity, phase, structural, morphological and optical properties of activated carbon were investigated using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscope (TEM), and UV-visible spectroscopy analysis. The graphitic phase of carbon was obtained from the XRD pattern. Surface morphology reveals irregular-shaped nanoparticles. The photodegradation of methylene blue (MB) was carried out under the visible light irradiation technique to study its photocatalytic activity. The activated carbon obtained at 400oC, 500oC and 600oC shows a photocatalytic degradation efficiency of 86%, 90%, and 94%, respectively. Antibacterial activity of activated carbon was examined against S. Aureus (MTCC-737) and E-Coli (MTCC- 443) microbial pathogens, and their potent antibacterial activity was examined from the zone of inhibition layer.


2017 ◽  
Vol 16 (02) ◽  
pp. 1650029
Author(s):  
R. Sepahvand ◽  
S. Alihosseini ◽  
M. Adeli ◽  
P. Sasanpour

Hybrid nanomaterials consisting of functionalized fullerene and gold nanoparticle (NP) have been synthesized. Fullerene was functionalized by citric acid and used as reducing and capping agent for preparation of gold NPs. Functionalization of fullerene by use of citric acid was performed by enzymatic and thermal approaches. The core-shell structures containing gold NPs as core and fullerene as shell (gold/fullerene) were prepared. It was found that method and density of functionalization of fullerene effect final structure and therefore their physicochemical property of hybrid nanomaterial dramatically. Ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), atomic force microscopy (AFM), transmission electron microscopy (TEM) were used to analyze the structure of the synthesized hybrid nanomaterial and also study their self-assembly and physicochemical properties. Effect of the size, structure and morphology (e.g., agglomeration) of the synthesized hybrid nanomaterial on their UV-Vis absorption behavior has been also verified by theoretical modeling.


2014 ◽  
Vol 1584 ◽  
Author(s):  
Matheswaran BALAMURUGAN ◽  
Shanmugam SARAVANAN ◽  
Naoki OHTANI

ABSTRACTSilver nanoparticle (AgNP) is one of the elegant material because its uses in various fields. In this study, AgNPs have been prepared by using Peltophorum pterocarpum (PP) flower extract as reducing and capping agent and aqueous silver nitrate (aq.AgNO3) as silver precursor. The synthesized nanoparticles were characterized using Ultra Violet - Visible (UV-Vis) spectroscopy, High Resolution Transmission Electron Microscope (HR-TEM) and Fourier Transform Infrared Spectroscopy (FT-IR), which reveals the formation of nanosized particles. The UV-Vis spectrum shows an absorption peak around 430nm. HR-TEM images of AgNPs with clear morphology and well dispersed prepared AgNPs.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Su-Ryeon Yun ◽  
Gyeong-Ok Kim ◽  
Chan Woo Lee ◽  
Nam-Ju Jo ◽  
Yongku Kang ◽  
...  

Polyaniline (Pani) and polypyrrole (Ppy) half hollow spheres with different shell thicknesses were successfully synthesized by three steps process using polystyrene (PS) as the core. The PS core was synthesized by emulsion polymerization. Aniline and pyrrole monomers were polymerized on the surface of the PS core. The shells of Pani and Ppy were fabricated by adding different amounts of aniline and pyrrole monomers. PS cores were dissolved and removed from the core shell structure by solvent extraction. The thicknesses of the Pani and Ppy half hollow spheres were observed by FE-SEM and FE-TEM. The chemical structures of the Pani and Ppy half hollow spheres were characterized by FT-IR spectroscopy and UV-Vis spectroscopy. The shell thicknesses of the Pani half hollow spheres were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, while the shell thicknesses of the Ppy half hollow spheres were 16.0, 22.0, 27.0, and 34.0 nm. The shell thicknesses of Pani and Ppy half hollow spheres linearly increased as the amount of the monomer increased. Therefore, the shell thickness of the Pani and Ppy half hollow spheres can be controlled in these ranges.


2017 ◽  
Vol 21 (01) ◽  
pp. 16-23 ◽  
Author(s):  
Sibel Eken Korkut ◽  
Hale Ocak ◽  
Belkıs Bilgin-Eran ◽  
Dilek Güzeller ◽  
M. Kasım Şener

The novel metal free phthalocyanine and its copper complex which are octa-substituted at the peripheral positions with 4-(([Formula: see text]-3,7-dimethlyoctyloxy)phenoxy moieties were synthesized and characterized by FT-IR, 1H NMR and mass spectroscopy. Their mesomorphic properties were studied by polarizing optical microscopy. The spectroscopic properties and aggregation behaviors of the novel phthalocyanines were also investigated by UV-vis spectroscopy in different solvents with same concentration as well as in a wide range of concentrations of chloroform. Both compounds with chloroform and [Formula: see text]-dodecane clearly show the lyotropic columnar mesophase in a wide temperature range whereas thermotropic liquid crystalline behavior for both compounds is not observed. Both of these novel compounds show no aggregation in toluene, tetrahydrofuran, dichloromethane and chloroform.


2020 ◽  
Vol 98 (2) ◽  
pp. 66-73 ◽  
Author(s):  
Celia Ferrag ◽  
Maryam Abdinejad ◽  
Kagan Kerman

Carbon dioxide (CO2) is an environmentally harmful “greenhouse gas” that is present in abundant quantities in the earth’s atmosphere. Thus, the sequestration and conversion of CO2 to value-added organic chemicals is of environmental and economical importance. In this proof-of-concept study, amine groups of acrylamide compounds were found to react with CO2 under ambient conditions to form a polyacrylamide hydrogel. This composite was characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR) and electrospray ionization mass spectrometry (ESI–MS), which confirmed successful synthesis and demonstrated all characteristics representative of a typical hydrogel material. Rheology analyses further proved the formation of the hydrogel, as well as its self-healing nature. The novel approach proposed in this work can potentially be used in the construction of versatile amine-based gel materials for efficient CO2 utilization applications.


Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3983
Author(s):  
Elżbieta Szczepańska ◽  
Beata Grobelna ◽  
Jacek Ryl ◽  
Amanda Kulpa ◽  
Tadeusz Ossowski ◽  
...  

In this paper, we described the synthesis procedure of TiO2@SiO2 core-shell modified with 3-(aminopropyl)trimethoxysilane (APTMS). The chemical attachment of Fmoc–glycine (Fmoc–Gly–OH) at the surface of the core-shell structure was performed to determine the amount of active amino groups on the basis of the amount of Fmoc group calculation. We characterized nanostructures using various methods: transmission electron microscope (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) to confirm the modification effectiveness. The ultraviolet-visible spectroscopy (UV-vis) measurement was adopted for the quantitative determination of amino groups present on the TiO2@SiO2 core-shell surface by determination of Fmoc substitution. The nanomaterials were functionalized by Fmoc–Gly–OH and then the fluorenylmethyloxycarbonyl (Fmoc) group was cleaved using 20% (v/v) solution of piperidine in DMF. This reaction led to the formation of a dibenzofulvene–piperidine adduct enabling the estimation of free Fmoc groups by measurement the maximum absorption at 289 and 301 nm using UV-vis spectroscopy. The calculations of Fmoc loading on core-shell materials was performed using different molar absorption coefficient: 5800 and 6089 dm3 × mol−1 × cm−1 for λ = 289 nm and both 7800 and 8021 dm3 × mol−1 × cm−1 for λ = 301 nm. The obtained results indicate that amount of Fmoc groups present on TiO2@SiO2–(CH2)3–NH2 was calculated at 6 to 9 µmol/g. Furthermore, all measurements were compared with Fmoc–Gly–OH used as the model sample.


NANO ◽  
2013 ◽  
Vol 08 (03) ◽  
pp. 1350032 ◽  
Author(s):  
CHUNNIAN CHEN ◽  
CHENWEI YU ◽  
WEN FU

GO/ Cu2O nanocomposite had been successfully synthesized by electrostatic interactions method. X-ray powder diffraction (XRD), transmission electron microscope (TEM), selective-area electron diffraction (SAED), Fourier transform infrared spectroscopy (FT-IR) and Raman spectra confirmed the structure of the Cu2O and GO/ Cu2O nanocomposite. The catalytic degradation of Rhodamine B under the condition of ultrasound was investigated and the result of UV-Vis spectroscopy demonstrated that the nanocomposite can efficiently degraded it.


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